Method and apparatus for mapping backhaul channels in a wireless system

ABSTRACT

In an exemplary embodiment, a method of a distributed unit (DU) in a wireless communication system is provided. The method comprises receiving information from a central unit (CU), identifying a bearer or group of bearers based on the information, and assigning the bearer or group of bearers to a backhaul channel.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a 371 of International Application No.PCT/KR2020/010724, filed Aug. 13, 2020, which claims priority to UnitedKingdom Patent Application No. 1911716.7, filed Aug. 15, 2019, thedisclosures of which are herein incorporated by reference in theirentirety.

BACKGROUND 1. Field

The present disclosure relates to wireless communication systems. Moreparticularly, the present disclosure relates to bearer mapping.

2. Description of Related Art

To meet the demand for wireless data traffic having increased sincedeployment of 4th generation (4G) communication systems, efforts havebeen made to develop an improved 5th generation (5G) or pre-5Gcommunication system. The 5G or pre-5G communication system is alsocalled a ‘beyond 4G network’ or a ‘post long term evolution (LTE)system’. The 5G communication system is considered to be implemented inhigher frequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplishhigher data rates. To decrease propagation loss of the radio waves andincrease the transmission distance, the beamforming, massivemultiple-input multiple-output (MIMO), full dimensional MIMO (FD-MIMO),array antenna, an analog beamforming, and large scale antenna techniquesare discussed with respect to 5G communication systems. In addition, in5G communication systems, development for system network improvement isunder way based on advanced small cells, cloud radio access networks(RANs), ultra-dense networks, device-to-device (D2D) communication,wireless backhaul, moving network, cooperative communication,coordinated multi-points (CoMP), reception-end interference cancellationand the like.

In the 5G system, hybrid frequency shift keying (FSK) and Feher'squadrature amplitude modulation (FQAM) and sliding window superpositioncoding (SWSC) as an advanced coding modulation (ACM), and filter bankmulti carrier (FBMC), non-orthogonal multiple access (NOMA), and sparsecode multiple access (SCMA) as an advanced access technology have beendeveloped.

The Internet, which is a human centered connectivity network wherehumans generate and consume information, is now evolving to the Internetof things (IoT) where distributed entities, such as things, exchange andprocess information without human intervention. The Internet ofeverything (IoE), which is a combination of the IoT technology and thebig data processing technology through connection with a cloud server,has emerged. As technology elements, such as “sensing technology”,“wired/wireless communication and network infrastructure”, “serviceinterface technology”, and “security technology” have been demanded forIoT implementation, a sensor network, a machine-to-machine (M2M)communication, machine type communication (MTC), and so forth have beenrecently researched. Such an IoT environment may provide intelligentInternet technology services that create a new value to human life bycollecting and analyzing data generated among connected things. IoT maybe applied to a variety of fields including smart home, smart building,smart city, smart car or connected cars, smart grid, health care, smartappliances and advanced medical services through convergence andcombination between existing information technology (IT) and variousindustrial applications.

In line with this, various attempts have been made to apply 5Gcommunication systems to IoT networks. For example, technologies such asa sensor network, MTC, and M2M communication may be implemented bybeamforming, MIMO, and array antennas. Application of a cloud RAN as theabove-described big data processing technology may also be considered tobe as an example of convergence between the 5G technology and the IoTtechnology.

As described above, various services can be provided according to thedevelopment of a wireless communication system, and thus a method foreasily providing such services is required.

SUMMARY

In an exemplary embodiment, A method of a distributed unit (DU) in awireless communication system is provided. The method comprisesreceiving information from a central unit (CU), identifying a bearer orgroup of bearers based on the information, and assigning the bearer orgroup of bearers to a backhaul channel.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure and itsadvantages, reference is now made to the following description taken inconjunction with the accompanying drawings, in which like referencenumerals represent like parts:

FIG. 1 illustrates a representation of part of a network employing IABaccording to embodiments of the present disclosure;

FIG. 2 illustrates a protocol stack illustrating Backhaul Adaptation(BAP) according to embodiments of the present disclosure;

FIG. 3 illustrates a gNB having a CU and DU according to embodiments ofthe present disclosure;

FIG. 4 illustrates a packet header structure according to IPv6 accordingto embodiments of the present disclosure;

FIG. 5 illustrates a packet header structure according to IPv4 accordingto embodiments of the present disclosure;

FIG. 6 illustrates a flow chart of the distributed unit (DU) accordingto embodiments of the present disclosure;

FIG. 7 illustrates a flow chart of the central unit (CU) according toembodiments of the present disclosure;

FIG. 8 schematically illustrates a block diagram of a base stationaccording to embodiments of the present disclosure;

FIG. 9 illustrates a block diagram of the central unit (CU) according toembodiments of the present disclosure; and

FIG. 10 illustrates a block diagram of the distributed unit (DU)according to embodiments of the present disclosure.

DETAILED DESCRIPTION

In an embodiment, a method of mapping a bearer or group of bearers to abackhaul channel, at a Distributed Unit, DU, in an Integrated Access andBackhaul, IAB, network is provided. The method comprising the step of:identifying a bearer or a group of bearers using information receivedfrom an associated Central Unit, CU, included in a packet header in oneof a plurality of possible fields, wherein the plurality of possiblefields includes: DS/DSCP, ECN, TOS/TC and Flow Label; and assigning thebearer or group of bearers to a backhaul channel.

In an embodiment, wherein the step of identifying is based on GTP tunnelID, TEID, of the bearer.

In an embodiment, wherein the step of identifying the bearer or a groupof bearers uses information included in a packet header in more than oneof the plurality of possible fields.

In an embodiment, wherein the more than one of the plurality of possiblefields includes one of the combinations: Flow Label field and TC field;Flow Label field and DS field; Flow Label field and ECN field; DSCPfield and ECN field; and DS field and ECN field.

In an embodiment, wherein the step of identifying the bearer or a groupof bearers further comprises the further step of indicating an actionassociated with the bearer or group of bearers.

In an embodiment, wherein: the DS/DSCP field identifies the bearer orgroup of bearers and the ECN field indicates the action; or the DS fieldor TC field identifies the bearer or group of bearers and the Flow Labelfield indicates the action; or the Flow Label field identifies thebearer or group of bearers and the DS field or TC field indicates theaction.

In an embodiment, wherein the action includes one or more of thefollowing: assigning a high priority; assigning a low priority;assigning a QoS class; randomizing flow; and assign a redundancy status

In an embodiment, wherein identifying a group of bearers comprisesgrouping on the basis of QoS requirements.

In an embodiment, wherein information on which of the plurality ofpossible fields comprises which information is indicated by means of areserved value of one or more of the fields themselves or by a flag.

In an embodiment, wherein the DU is one of a donor DU or an IAB DU.

In an embodiment, wherein if the DU is part of an IAB node, the fullinformation, or a subset of information thereof, from the DS/DSCP orTC/TOS field and/or flow label, as applicable, is inserted into a BAPheader.

In an embodiment, wherein a donor Central Unit, CU, configures a donorDU and all intermediate nodes on what the full information in the BAPheader represents.

In an embodiment, wherein if the DU is part of an IAB node, the beareridentifying information from the DS/DSCP or TC/TOS field and/or flowlabel, as applicable, is inserted into a BAP header.

In an embodiment, wherein the donor DU configures additional informationfor the BAP header, based on bearer identity.

In an embodiment, wherein the donor CU configures the donor DU and allintermediate nodes with additional information, which is mapped tobearer ID contained in the BAP header at the intermediate nodes.

In an embodiment, a method of a distributed unit (DU) in a wirelesscommunication system is provided. The method comprising: receivinginformation from a central unit (CU); identifying a bearer or group ofbearers based on the information; and assigning the bearer or group ofbearers to a backhaul channel.

In an embodiment, wherein the bearer or the group of bearers isidentified based on a GTP(GPRS Tunnelling Protocol) tunnel ID of thebearer.

In an embodiment, wherein the information is included in a packetheader.

In an embodiment, wherein the bearer or the group of bearers areidentified based on at least one of information of Flow Label field,Differentiated Services (DS) field, Differentiated Services Code Point(DSCP) field, Traffic Class (TC) field or Explicit CongestionNotification (ECN) field in a packet.

In an embodiment, wherein the DU is included in a donor base station(BS) in an integrated access and backhaul (IAB) network.

In an embodiment, a method of a central unit (CU) in a wirelesscommunication system is provided. The method comprising: transmittinginformation to a distributed unit (DU); and wherein a bearer or group ofbearers is identified based on the information; and wherein the beareror group of bearers is assigned to a backhaul channel.

In an embodiment, wherein the bearer or the group of bearers isidentified based on a GTP(GPRS Tunnelling Protocol) tunnel ID of thebearer.

In an embodiment, wherein the information is included in a packetheader.

In an embodiment, wherein the bearer or the group of bearers areidentified based on at least one of information of Flow Label field,Differentiated Services (DS) field, Differentiated Services Code Point(DSCP) field, Traffic Class (TC) field or Explicit CongestionNotification (ECN) field in a packet.

In an embodiment, wherein the DU and CU are included in a donor basestation (BS) in an integrated access and backhaul (IAB) network.

MODE FOR INVENTION

Other technical features may be readily apparent to one skilled in theart from the following figures, descriptions, and claims.

According to the present disclosure there is provided an apparatus andmethod as set forth in the appended claims. Other features of thedisclosure will be apparent from the dependent claims, and thedescription which follows.

Before undertaking the DETAILED DESCRIPTION below, it can beadvantageous to set forth definitions of certain words and phrases usedthroughout this disclosure. The term “couple” and its derivatives referto any direct or indirect communication between two or more elements,whether or not those elements are in physical contact with one another.The terms “transmit,” “receive,” and “communicate,” as well asderivatives thereof, encompass both direct and indirect communication.The terms “include” and “comprise,” as well as derivatives thereof, meaninclusion without limitation. The term “or” is inclusive, meaningand/or. The phrase “associated with,” as well as derivatives thereof,means to include, be included within, interconnect with, contain, becontained within, connect to or with, couple to or with, be communicablewith, cooperate with, interleave, juxtapose, be proximate to, be boundto or with, have, have a property of, have a relationship to or with, orthe like. The term “controller” means any device, system or part thereofthat controls at least one operation. Such a controller can beimplemented in hardware or a combination of hardware and software and/orfirmware. The functionality associated with any particular controllercan be centralized or distributed, whether locally or remotely. Thephrase “at least one of,” when used with a list of items, means thatdifferent combinations of one or more of the listed items can be used,and only one item in the list can be needed. For example, “at least oneof: A, B, and C” includes any of the following combinations: A, B, C, Aand B, A and C, B and C, and A and B and C.

Moreover, various functions described below can be implemented orsupported by one or more computer programs, each of which is formed fromcomputer readable program code and embodied in a computer readablemedium. The terms “application” and “program” refer to one or morecomputer programs, software components, sets of instructions,procedures, functions, objects, classes, instances, related data, or aportion thereof adapted for implementation in a suitable computerreadable program code. The phrase “computer readable program code”includes any type of computer code, including source code, object code,and executable code. The phrase “computer readable medium” includes anytype of medium capable of being accessed by a computer, such as readonly memory (ROM), random access memory (RAM), a hard disk drive, acompact disc (CD), a digital video disc (DVD), or any other type ofmemory. A “non-transitory” computer readable medium excludes wired,wireless, optical, or other communication links that transporttransitory electrical or other signals. A non-transitory computerreadable medium includes media where data can be permanently stored andmedia where data can be stored and later overwritten, such as arewritable optical disc or an erasable memory device.

Definitions for other certain words and phrases are provided throughoutthis disclosure. Those of ordinary skill in the art should understandthat in many, if not most, instances, such definitions apply to prior aswell as future uses of such defined words and phrases.

In an exemplary embodiment according to the present disclosure, methodsfor identifying bearer and mapping to backhaul channels are provided.

FIGS. 1 through 10, discussed below, and the various embodiments used todescribe the principles of the present disclosure in this disclosure areby way of illustration only and should not be construed in any way tolimit the scope of the disclosure. Those skilled in the art willunderstand that the principles of the present disclosure can beimplemented in any suitably arranged wireless communication system.

Depending on the network type, the term ‘base station’ can refer to anycomponent (or collection of components) configured to provide wirelessaccess to a network, such as a transmit point (TP), a TRP, a gNB, amacrocell, a femtocell, a WiFi access point (AP), or other wirelesslyenabled devices. Base stations can provide wireless access in accordancewith one or more wireless communication protocols, e.g., 5G 3GPP NewRadio Interface/Access (NR), long term evolution (LTE), LTE advanced(LTE-A), High Speed Packet Access (HSPA), Wi-Fi 802.11a/b/g/n/ac, etc.The terms ‘gNB’ and ‘TRP’ can be used interchangeably in this disclosureto refer to network infrastructure components that provide wirelessaccess to remote terminals. Also, depending on the network type, theterm UE can refer to any component such as mobile station, subscriberstation, remote terminal, wireless terminal, receive point, or userdevice. A UE can be a mobile device or a stationary device.

To meet the demand for wireless data traffic having increased sincedeployment of 4G communication systems, efforts have been made todevelop an improved 5G or pre-5G communication system. Therefore, the 5Gor pre-5G communication system is also called a ‘Beyond 4G Network’ or a‘Post LTE System’.

A 5G communication system can be implemented in higher frequency(mmWave) bands, such as 28 GHz or 60 GHz bands or, in general, above 6GHz bands, so as to accomplish higher data rates, or in lower frequencybands, such as below 6 GHz, to enable robust coverage and mobilitysupport. To decrease propagation loss of the radio waves and increasethe transmission distance, the beamforming, massive multiple-inputmultiple-output (MIMO), Full Dimensional MIMO (FD-MIMO), array antenna,an analog beam forming, large scale antenna techniques are considered in5G communication systems. In addition, in 5G communication systems,development for system network improvement is under way based onadvanced small cells, cloud Radio Access Networks (RANs), ultra-densenetworks, device-to-device (D2D) communication on sidelink, wirelessbackhaul, moving network, cooperative communication, CoordinatedMulti-Point (CoMP) transmissions/receptions such as from multiple TRPs,reception-end interference cancellation and the like.

The discussion of 5G systems and frequency bands associated therewith isfor reference as certain embodiments of the present disclosure can beimplemented in 5G systems. However, the present disclosure is notlimited to 5G systems or the frequency bands associated therewith, andembodiments of the present disclosure can be utilized in connection withany frequency band.

FIG. 1 illustrates a representation of part of a network employingIntegrated Access and Backhaul (IAB) according to embodiments of thepresent disclosure.

According to the present disclosure, method and apparatus forimprovements in and relating to bearer identification and mapping may beprovided. The present disclosure relates to bearer mapping. Itparticularly relates to bearer mapping in an Integrated Access andBackhaul (IAB) network. The bearer or groups of bearers (1:1 or N:1) aremapped onto a backhaul channel. IAB nodes are used in Fifth Generation(5G) or New Radio (NR) networks in particular but may have otherapplications.

Such an IAB configuration is shown in FIG. 1. Here, nodes are used asrelay nodes (rTRP) for the extension of wireless backhaul links up to anode which has a fibre/wired backhaul connection.

In FIG. 1, there are three nodes 10, 20, 30, each connected to one ormore UEs 50. Node 10 is provided with a fibre connection 40 to the corenetwork. Nodes 20, 30 do not have such a wired connection and make useof the access spectrum to provide backhaul connections to the wired basestation 10, which then transmits/receives the required data to/from thecore network.

By means of such a configuration, it is possible to install nodeswithout the necessity of providing a fibre data connection, therebyallowing speedy and simple roll out of base stations to locations whereno such data connection is available or possible.

FIG. 2 illustrates a protocol stack illustrating Backhaul Adaptation(BAP) according to embodiments of the present disclosure.

In standardization discussions, a new protocol layer has been defined,known as the Backhaul Adaptation Layer (BAP). Its relationship withother, known, layers is shown in FIG. 2, where the BAP layer isillustrated between the IP (Internet Protocol) and RLC (Radio LinkControl) layers of the protocol stack.

FIG. 2 shows the relative interconnections between an IAB Donor gNB 100,a first IAB node 110 and a second IAB node 120. The Backhaul RLC channelis shown between the donor gNB100 and the first IAB node 110, and alsobetween the first IAB node 110 and the second IAB node 120. The FIG. 2shows how F1-U is carried over two backhaul hops.

FIG. 3 illustrates a gNB having a CU and DU according to embodiments ofthe present disclosure.

FIG. 3 shows a gNB having a CU and DU. FIG. 3 shows a gNB 300. In thegNB 300, two main functional units may be categorised as a central unit(CU) 310 and a distributed unit (DU) 320. A gNB 300 may have more thanone DU associated with a given CU, located relatively distant from theCU. The interface between the CU and a respective DU is known as the F1interface. The F1 interface may be subdivided into F1-U interface 330and F1-C interface 340, based on User plane and Control planefunctionalities, respectively.

The primary purpose of the BAP is to transport the F1-U interface 330across the wireless backhaul.

FIG. 3 illustrates how a donor gNB is split into CU 310 and DU 320, asmentioned above. The gNB-DU functionality terminates NR access to UEsand IAB nodes and supports F1 protocol to the gNB-CU on the IAB-donor.

In standardization discussions, various agreements/assumptions have beenmade. These agreements/assumptions include adopting IPv6 Flow Labels for1:1 mapping (in conjunction with IAB node IP address). For N:1 mapping,both DSCP-based and IPv6 flow-label based mapping may be used in thedonor DU for downlink (DL), with both coexisting in the same network.

In accordance with standardization discussions, GTP Tunnel id, whichuniquely identifies each bearer under the same CU, is mapped to the IPv6Flow Label at the CU. In the case of 1:1 mapping of bearers to backhaulRLC channels, the DU then uses the IPv6 Flow Label field todifferentiate among bearers.

However, an issue arises in the use of the Flow Label field and inwhether additional fields in the IPv6 headers are used to aid mapping.In the case of N:1 mapping, there is even less conformity and mattersare not yet agreed at a standardization level. Furthermore, it has notbeen agreed whether the mapping (at the donor DU) information referredto above is inserted into the BAP header for use by intermediate nodes.

In an IPv4 environment, the Flow Label field is not available and sodifferent but related issues apply.

The issues referred to above, as well as others not explicitlymentioned, are addressed by embodiments of the present disclosure.

According to a first aspect of the present disclosure, there is provideda method of mapping a bearer or group of bearers to a backhaul channel,at a Distributed Unit (DU), in an Integrated Access and Backhaul (IAB)network, comprising the step of: identifying a bearer or a group ofbearers using information received from an associated Central Unit (CU)included in a packet header in one of a plurality of possible fields,wherein the plurality of possible fields includes: DifferentiatedServices (DS)/Differentiated Services Code Point (DSCP), ExplicitCongestion Notification (ECN), Type of Service (TOS)/Traffic Class (TC)and Flow Label; and assigning the bearer or group of bearers to abackhaul channel.

In an embodiment, the step of identifying is based on GTP tunnel ID,TED, of the bearer. For instance, one or more of the following mapapply: bearer ID identical to the tunnel ID; bearer ID equal to the Nmost/least significant bits of the tunnel ID; bearer ID representing QoSof bearer, where this case is applicable to both 1:1 and N:1 mappings.

In an embodiment, the step of identifying the bearer or a group ofbearers uses information included in a packet header in more than one ofthe plurality of possible fields.

In an embodiment, the more than one of the plurality of possible fieldsincludes one of the combinations: Flow Label field and TC field; FlowLabel field and DS field; Flow Label field and ECN field; DSCP field andECN field; and DS field and ECN field.

In an embodiment, the step of identifying the bearer or a group ofbearers further comprises the further step of indicating an actionassociated with the bearer or group of bearers.

In an embodiment: the DS/DSCP field identifies the bearer or group ofbearers and the ECN field indicates the action; or the DS field or TCfield identifies the bearer or group of bearers and the Flow Label fieldindicates the action; or the Flow Label field identifies the bearer orgroup of bearers and the DS field or TC field indicates the action.

In an embodiment, the action includes one or more of the following:assigning a high priority; assigning a low priority; assigning a QoSclass; randomizing flow; and assign a redundancy status

In an embodiment, identifying a group of bearers comprises grouping onthe basis of QoS requirements.

In an embodiment, information on which of the plurality of possiblefields comprises which information is indicated by means of a reservedvalue of one or more of the fields themselves or by a flag.

In an embodiment, the DU is one of a donor DU or an IAB DU.

In an embodiment, if the DU is part of an IAB node, the fullinformation, or a subset of information thereof, from the DS/DSCP orTC/TOS field and/or flow label, as applicable, is inserted into a BAPheader.

In an embodiment, a donor Central Unit, CU, configures a donor DU andall intermediate nodes on what the full information in the BAP headerrepresents.

In an embodiment, if the DU is part of an IAB node, the beareridentifying information from the DS/DSCP or TC/TOS field and/or flowlabel, as applicable, is inserted into a BAP header

In an embodiment, the donor DU configures additional information for theBAP header, based on bearer identity.

In an embodiment, the donor CU configures the donor DU and allintermediate nodes with additional information, which is mapped tobearer ID contained in the BAP header at the intermediate nodes.

It should be noted that, depending on the context, certain terms areused in IPv4 and IPv6 to relate to the same or substantially the samefeatures. For instance, in IPv4, the Type of Service (TOS) fieldincludes sub fields Differentiated Services Code Point (DSCP) andExplicit Congestion Notification (ECN). In IPv6, the Traffic Class (TC)field includes sub fields Differentiated Services (DS) and ExplicitCongestion Notification (ECN). In effect, TC and TOS are equivalents inthe different versions of the standard. Similarly, DS and DSCP areequivalents in the different versions of the standard. References to TOSshould, where appropriate, depending upon context, be understood torefer equally to TC and vice-versa. Similarly, references to DSCPshould, where appropriate, depending upon context, be understood torefer equally to DS and vice-versa. Where reference is made to TOS/TC orDSCP/DS, it is to be understood that the terminology appropriate to therelevant version of the standard is intended.

In an embodiment of the present disclosure, in the case of 1:1 bearermapping, bearer mapping is performed at the Donor DU, whereby the flowlabel field (only present in IPv6 systems) is used to uniquely identifya bearer. This provides a sufficient bearer space size. However, sincethe IPv6 header also includes TC/TOS (Traffic Class or Type of Service)field, which in turn comprises DSCP and ECN fields, each of which may beavailable for purposes other than their original ones, the flow labelfield combined with the TC/TOS field or a part of the TC/TOS field (i.e.just DSCP or just ECN) can also be used to uniquely identify a bearer.

Furthermore, in a case where the flow label uniquely identifies abearer, reserved values of DS/DSCP or TC/TOS may be used to indicatecertain specific actions. For example, the TC/TOS field or a part of theTC/TOS field can indicate priority levels (e.g. this packet should beprioritized in cases of congestion or dropped if needed), QoS class,randomization (e.g. this packet can go via any available path for thespecific destination), packet duplication.

In IPv4 networks, the flow label field does not exist. In IPv4 networksit is therefore possible to use the DSCP field to uniquely identify abearer. It should be noted that this method is not limited to IPv4networks but is perhaps more applicable in this scenario due to absenceof flow label.

Additionally, the DSCP field combined with ECN field can be used touniquely identify a bearer. Alternatively, rather than being used aspart of the bearer ID, it is possible to indicate specific actions usingreserved values of the ECN field. For example, the ECN field may be usedto indicate priority levels (e.g. this packet should be prioritized incases of congestion or dropped if needed), QoS class, randomization(e.g. this packet can go via any available path for the specificdestination), packet duplication.

In the case of N:1 bearer mapping, the DS/DSCP field can be used togroup together multiple bearers for transmission over the same BH RLCchannel, e.g. based on the same/similar QoS requirements. Using the samereasoning applied to the ECN case above, in the case of IPv6 systemswhere the DS/DSCP field (or the TC/TOS field) is used to group togethermultiple bearers, the flow label field may, in this case, indicatepriority levels (e.g. this packet should be prioritized in cases ofcongestion or dropped if needed), QoS class, randomization (e.g. thispacket can go via any available path for the specific destination),packet duplication.

In IPv6 systems, it is also possible to use the flow label for the N:1mapping case, and the TC/TOS or DS/DSCP fields to indicate specialconditions or actions. This may be considered, essentially, as theinverse approach to the one detailed above.

In other words, an embodiment provides bearer mapping at the Donor DUwhereby the flow label field is used to group together multiple bearersfor transmission over the same BH RLC channel e.g. based on QoSrequirements. Reserved values of DS/DSCP or TC/TOS field can be used toindicate one or more of specific actions to be taken with the packets ofthe aggregated bearers.

In a broad form it is possible to define an embodiment of the presentdisclosure according to one of the following statements:

a. Either DSCP/ECN/TOS or flow label indicates bearer identity or theidentity of a group of bearers

b. DSCP/ECN/TOS and flow label combined indicate bearer identity or theidentity of a group of bearers

c. DSCP/ECN/TOS and flow label combined indicate bearer identity andadditional information

In the IPv4-specific case:

a. Either DSCP or ECN indicate bearer identity or the identity of agroup of bearers

b. DSCP and ECN combined indicate bearer identity or the identity of agroup of bearers

c. DSCP and ECN combined indicate bearer identity and additionalinformation

The specific option (a/b/c) above is indicated by a reserved value ofthe DCSP/TOS/ECN field, or a reserved value of the flow label, or aflag. The additional information could further include: QoS class,priority, information that this packet is being retransmitted,instruction to duplicate the packet, number of hops this packets needsto traverse to its destination.

Embodiments thus far have focused on operation at the Donor node.However, embodiments also relate to intermediate nodes in the IABnetwork which follow the same procedures as those detailed for the DonorDU above. This can be achieved by inserting the full information fromthe DS/DSCP or TC/TOS field and/or flow label (as applicable/needed)into the BAP header. It can also be achieved by inserting a subset ofthe information from the DS/DSCP or TC/TOS field (as applicable/needed)and/or flow label into the BAP header, e.g. just the bearer ID or justthe additional information.

The most straightforward method of configuring the BAP header, accordingto above scenarios involves the flow label field (plus any additionalinfo) being set by donor CU and copied into the BAP header. The donor CUconfigures donor DU and all intermediate nodes on what the flow label(plus additional info) in the BAP header represents.

Embodiments of the disclosure include the case where the donor DU (basedon flow label plus any additional info) configures the additionalinformation for the BAP header based on the mapping information.Additionally, the donor CU configures the donor DU and all intermediatenodes with additional information (which can change from node to node),which is mapped to bearer ID contained in the BAP header at theintermediate nodes.

According to a further aspect of the present disclosure, there isprovided a method of mapping a bearer or group of bearers, in an IPv6environment, at a Distributed Unit, DU, in an Integrated Access andBackhaul, IAB, network, comprising the step of: identifying a bearer ora group of bearers using information included in a packet header in aTraffic Class field or a Flow Label field.

According to a still further aspect of the present disclosure, there isprovided a method of mapping a bearer or group of bearers, in an IPv4environment, at a Distributed Unit, DU, in an Integrated Access andBackhaul, IAB, network, comprising the step of: identifying a bearer ora group of bearers using information included in a packet header in aDSCP or ECN field.

FIG. 4 illustrates a packet header structure according to IPv6 accordingto embodiments of the present disclosure. According to an embodiment ofthe present disclosure, there is provided a method of bearer mapping atthe DU of a donor gNB, whereby the Flow Label field, present in thepacket header in IPv6, is used to uniquely identify a bearer. In afurther embodiment, the Flow Label field is combined with all or part ofthe Traffic Class (TC) field to uniquely identify a bearer. Sub fieldswithin the TC field are the Differentiated Services (DS) fieldcomprising 6 bits and the Explicit Congestion Notification (ECN) fieldcomprising 2 bits.

FIG. 4 shows a representation of the header of a data packet accordingto IPv6. The 8 bits which form Traffic Class (TC), comprising DS and ECNare shown.

FIG. 5 illustrates a packet header structure according to IPv4 accordingto embodiments of the present disclosure.

In IPv4 networks, the Flow Label field does not exist and so a differenttechnique is required. Here, bearer mapping at the donor DU uses theDifferentiated Services Code Point (DSCP) field to uniquely identify abearer. DSCP is a sub field within the Type of Service (TOS) field,comprising 6 bits. The other sub field within TOS is Explicit CongestionNotification (ECN) comprising 2 bits.

FIG. 5 shows a representation of the header of a data packet accordingto IPv4. The 8 bits which form TOS, comprising DSCP and ECN are shown.

In a further embodiment, a combination of data stored in the DSCP andECN fields is used to uniquely identify a bearer.

It should be noted that this technique is not restricted only to IPv4networks but is particularly useful in the absence of the Flow Labelfield, which is found in IPv6.

In a still further embodiment, instead of being used to identify abearer, data stored in the ECN field is used to indicate one or more of:

-   -   Priority—this packet should be prioritized in cases of        congestion    -   Low priority—this packet can be dropped if needed    -   QoS class—signifying a level of QoS assigned to the packet    -   Randomizing flow—this packet can go via any available path for        this destination    -   Redundancy—duplicate this packet

In the above list, a reference to packet includes all packets in onebearer or a group of bearers (as appropriate), since packets in thesescenarios will necessarily be handled together.

In a still further embodiment, mapping at the donor DU uses the DS/DSCPfield to group multiple bearers together for transmission over the sameBH RLC channel (N:1 mapping). Furthermore, this mapping may be performedon the basis of QoS requirements. Here, all bearers having the same orsimilar QoS are grouped together, since they will then be routedidentically and so will experience the same QoS.

When the DS/DSCP field or TC/TOS field is used to group togethermultiple bearers, then the Flow Label field (present in IPv6) may beused to indicate one or more of:

-   -   Priority—this packet should be prioritized in cases of        congestion    -   Low priority—this packet can be dropped if needed    -   QoS class—signifying a level of QoS assigned to the packet    -   Randomizing flow—this packet can go via any available path for        this destination    -   Redundancy—duplicate this packet

In an embodiment, as mentioned, the Flow Label field is used to uniquelyid a bearer. A further refinement is to use DS/DSCP or TC/TOS field toindicate one or more of:

-   -   Priority—this packet should be prioritized in cases of        congestion    -   Low priority—this packet can be dropped if needed    -   QoS class—signifying a level of QoS assigned to the packet    -   Randomizing flow—this packet can go via any available path for        this destination    -   Redundancy—duplicate this packet

In an embodiment, there is provided a method of bearer mapping at thedonor DU whereby the Flow Label field is used to group multiple bearersover the same BH RLC channel and whereby the grouping (N:1 mapping) isperformed based on QoS requirements, as mentioned previously. In thiscase, the TC/TOS or DS/DSCP field can indicate one or more of:

-   -   Priority—this packet should be prioritized in cases of        congestion    -   Low priority—this packet can be dropped if needed    -   QoS class—signifying a level of QoS assigned to the packet    -   Randomizing flow—this packet can go via any available path for        this destination    -   Redundancy—duplicate this packet

A reserved value in the DS/DSCP, ECN or TC/TOS field is used to indicatewhich particular embodiment described above is in use i.e. which fieldin the header includes which information.

In a further embodiment, intermediate nodes in the IAB network followthe same procedures as those specified for the Donor DU set out above.This can be enabled by inserting the full information from the DS/DSCPfield and/or Flow Label field into the BAP header. It can also beenabled by inserting a subset of the information from the DS/DSCP fieldand/or Flow Label field into the BAP header, e.g. just the bearer ID orjust the additional information, as required.

This method of configuring the BAP header assumes that the Flow Labelfield (plus any additional info) is set by the donor CU and copied intothe BAP header. The donor CU configures the donor DU and allintermediate nodes on what the Flow Label field (plus additional info)in the BAP header represents.

In a further embodiment, the donor DU (based on the Flow Label fieldplus any additional info) configures the additional information for theBAP header based on the mapping information.

In a further embodiment, the donor CU configures the donor DU and allintermediate nodes with additional information (which can change fromnode to node), which is mapped to bearer ID contained in the BAP headerat the intermediate nodes.

Although a few preferred embodiments of the present disclosure have beenshown and described, it will be appreciated by those skilled in the artthat various changes and modifications might be made without departingfrom the scope of the disclosure, as defined in the appended claims.

FIG. 6 illustrates a flow chart of the distributed unit (DU) accordingto embodiments of the present disclosure.

Since the detailed operation of the DU has been described above,repetitive content will be omitted in the following description.

The DU 320 may be included in the base station. For example, the DU 320may be IAB-donor DU or the donor DU. The DU 320 may be included in thebase station. In an embodiment, the DU 320 may be included in the in anIntegrated Access and Backhaul (IAB) network.

At step S610, the DU 320 may receive information from an associatedcentral unit (CU). In this case, the CU may be associated with the DU.

In an embodiment, the information includes at least one of flow label orDS information. For example, the flow label may mean IPv6 Flow Label.

In an embodiment, the information may be transferred included in amessage.

In an embodiment, the DU 320 may be included in a donor base station(BS)(for example, donor gNB). Also, the associated CU may be included inthe donor gNB.

At step S620, the DU 320 may identify a bearer or group of bearers basedon the information.

In an embodiment, the information received from the CU 310. Also, theinformation may be included in a packet header. For example, theinformation may be IP header information.

In an embodiment, the information included in a packet header (or IPheader information) may include at least one information of Flow Labelfield, Differentiated Services (DS) field, Differentiated Services CodePoint (DSCP) field, Traffic Class (TC) field or Explicit CongestionNotification (ECN) field in a packet.

In an embodiment, the bearer or the group of bearers may be identifiedbased on a GTP (GPRS Tunnelling Protocol) tunnel ID of the bearer.

In an embodiment, the bearer or the group of bearers are identifiedbased on at least one of information of Flow Label field, DifferentiatedServices (DS) field, Differentiated Services Code Point (DSCP) field,Traffic Class (TC) field or Explicit Congestion Notification (ECN) fieldin a packet.

At step S630, the DU may assign the bearer or group of bearers to abackhaul channel.

In an embodiment, the backhaul channel corresponds to the BH RLCchannel.

FIG. 7 illustrates a flow chart of the central unit (CU) according toembodiments of the present disclosure.

Since the detailed operation of the CU has been described above,repetitive content will be omitted in the following description.

The CU may be included in the base station. For example, the CU may beIAB-donor CU or the donor CU. The CU may be included in the basestation. In an embodiment, the CU may be included in the in anIntegrated Access and Backhaul (IAB) network.

At step S710, The CU may transmit information to a distributed unit (DU)

In an embodiment, a bearer or group of bearers may be identified basedon the information.

In an embodiment, the bearer or group of bearers may be assigned to abackhaul channel.

In an embodiment, the bearer or the group of bearers may be identifiedbased on a GTP(GPRS Tunnelling Protocol) tunnel ID of the bearer.

In an embodiment, the information may be included in a packet header.

In an embodiment, the bearer or the group of bearers may be identifiedbased on at least one of information of Flow Label field, DifferentiatedServices (DS) field, Differentiated Services Code Point (DSCP) field,Traffic Class (TC) field or Explicit Congestion Notification (ECN) fieldin a packet.

In an embodiment, the DU and CU may be included in a donor base station(BS) in an integrated access and backhaul (IAB) network.

FIG. 8 schematically illustrates a block diagram of a base stationaccording to embodiments of the present disclosure.

In an embodiment, the base station 800 may correspond to the gNB 300.

Referring to the FIG. 8, the base station 800 may include a processor810, a transceiver 820 and a memory 830. However, all of the illustratedcomponents are not essential. The base station 800 may be implemented bymore or less components than those illustrated in FIG. 8. In addition,the processor 810 and the transceiver 820 and the memory 830 may beimplemented as a single chip according to another embodiment.

The aforementioned components will now be described in detail.

The processor 810 may include one or more processors or other processingdevices that control the provided proposed function, process, and/ormethod. Operation of the base station 800 may be implemented by theprocessor 810.

The transceiver 820 may include a RF transmitter for up-converting andamplifying a transmitted signal, and a RF receiver for down-converting afrequency of a received signal. However, according to anotherembodiment, the transceiver 820 may be implemented by more or lesscomponents than those illustrated in components.

The transceiver 820 may be connected to the processor 810 and transmitand/or receive a signal. The signal may include control information anddata. In addition, the transceiver 820 may receive the signal through awireless channel and output the signal to the processor 810. Thetransceiver 820 may transmit a signal output from the processor 810through the wireless channel.

The memory 830 may store the control information or the data included ina signal obtained by the base station 800. The memory 830 may beconnected to the processor 810 and store at least one instruction or aprotocol or a parameter for the provided proposed function, process,and/or method. The memory 830 may include read-only memory (ROM) and/orrandom access memory (RAM) and/or hard disk and/or CD-ROM and/or DVDand/or other storage devices.

In an exemplary embodiment, the base station 800 may transmit aregistration accept message to the UE.

FIG. 9 illustrates a block diagram of the central unit (CU) according toembodiments of the present disclosure.

In an embodiment, the CU 9000 may be included in the base station 800.In an embodiment, the CU 900 may correspond to the CU 310.

Referring to the FIG. 9, the CU 900 may include a processor 910, atransceiver 920 and a memory 930. However, all of the illustratedcomponents are not essential. The CU 900 may be implemented by more orless components than those illustrated in FIG. 9. In addition, theprocessor 910 and the transceiver 920 and the memory 930 may beimplemented as a single chip according to another embodiment.

The aforementioned components will now be described in detail.

The processor 910 may include one or more processors or other processingdevices that control the provided proposed function, process, and/ormethod. Operation of the CU 900 may be implemented by the processor 910.

The transceiver 920 may include a RF transmitter for up-converting andamplifying a transmitted signal, and a RF receiver for down-converting afrequency of a received signal. However, according to anotherembodiment, the transceiver 920 may be implemented by more or lesscomponents than those illustrated in components.

The transceiver 920 may be connected to the processor 910 and transmitand/or receive a signal. The signal may include control information anddata. In addition, the transceiver 920 may receive the signal through awireless channel and output the signal to the processor 910. Thetransceiver 920 may transmit a signal output from the processor 910through the wireless channel.

The memory 930 may store the control information or the data included ina signal obtained by the CU 900. The memory 930 may be connected to theprocessor 910 and store at least one instruction or a protocol or aparameter for the provided proposed function, process, and/or method.The memory 930 may include read-only memory (ROM) and/or random accessmemory (RAM) and/or hard disk and/or CD-ROM and/or DVD and/or otherstorage devices.

In an embodiment, the processor 910 may be configured to transmitinformation to a distributed unit (DU); and wherein a bearer or group ofbearers is identified based on the information; and wherein the beareror group of bearers is assigned to a backhaul channel.

In an embodiment, the bearer or the group of bearers may be identifiedbased on a GTP(GPRS Tunnelling Protocol) tunnel ID of the bearer.

In an embodiment, the information may be included in a packet header.

In an embodiment, the bearer or the group of bearers may be identifiedbased on at least one of information of Flow Label field, DifferentiatedServices (DS) field, Differentiated Services Code Point (DSCP) field,Traffic Class (TC) field or Explicit Congestion Notification (ECN) fieldin a packet.

In an embodiment, wherein the DU and CU may be included in a donor basestation (BS).

FIG. 10 illustrates a block diagram of the distributed unit (DU)according to embodiments of the present disclosure.

In an embodiment, the DU 1000 may be included in the base station 800.In an embodiment, the DU 1000 may correspond to the DU 320.

Referring to the FIG. 10, the DU 1000 may include a processor 1010, atransceiver 1020 and a memory 1030. However, all of the illustratedcomponents are not essential. The DU 1000 may be implemented by more orless components than those illustrated in FIG. 10. In addition, theprocessor 1010 and the transceiver 1020 and the memory 1030 may beimplemented as a single chip according to another embodiment.

The aforementioned components will now be described in detail.

The processor 1010 may include one or more processors or otherprocessing devices that control the provided proposed function, process,and/or method. Operation of the DU 1000 may be implemented by theprocessor 1010.

The transceiver 1020 may include a RF transmitter for up-converting andamplifying a transmitted signal, and a RF receiver for down-converting afrequency of a received signal. However, according to anotherembodiment, the transceiver 1020 may be implemented by more or lesscomponents than those illustrated in components.

The transceiver 1020 may be connected to the processor 1010 and transmitand/or receive a signal. The signal may include control information anddata. In addition, the transceiver 1020 may receive the signal through awireless channel and output the signal to the processor 1010. Thetransceiver 1020 may transmit a signal output from the processor 1010through the wireless channel.

The memory 1030 may store the control information or the data includedin a signal obtained by the DU 1000. The memory 1030 may be connected tothe processor 1010 and store at least one instruction or a protocol or aparameter for the provided proposed function, process, and/or method.The memory 1030 may include read-only memory (ROM) and/or random accessmemory (RAM) and/or hard disk and/or CD-ROM and/or DVD and/or otherstorage devices.

In an embodiment, the processor 1010 may be configured to receiveinformation from a central unit (CU), identify a bearer or group ofbearers based on the information, and assign the bearer or group ofbearers to a backhaul channel.

In an embodiment, the processor 1010 may be configured to identify thebearer or the group of bearers based on a GTP(GPRS Tunnelling Protocol)tunnel ID of the bearer.

In an embodiment, wherein the information is included in a packetheader.

In an embodiment, the processor 1010 may be configured to identify thebearer or the group of bearers based on at least one of information ofFlow Label field, Differentiated Services (DS) field, DifferentiatedServices Code Point (DSCP) field, Traffic Class (TC) field or ExplicitCongestion Notification (ECN) field in a packet.

In an embodiment, the DU may be included in a donor base station (BS).

At least some of the example embodiments described herein may beconstructed, partially or wholly, using dedicated special-purposehardware. Terms such as ‘component’, ‘module’ or ‘unit’ used herein mayinclude, but are not limited to, a hardware device, such as circuitry inthe form of discrete or integrated components, a Field Programmable GateArray (FPGA) or Application Specific Integrated Circuit (ASIC), whichperforms certain tasks or provides the associated functionality. In someembodiments, the described elements may be configured to reside on atangible, persistent, addressable storage medium and may be configuredto execute on one or more processors. These functional elements may insome embodiments include, by way of example, components, such assoftware components, object-oriented software components, classcomponents and task components, processes, functions, attributes,procedures, subroutines, segments of program code, drivers, firmware,microcode, circuitry, data, databases, data structures, tables, arrays,and variables. Although the example embodiments have been described withreference to the components, modules and units discussed herein, suchfunctional elements may be combined into fewer elements or separatedinto additional elements. Various combinations of optional features havebeen described herein, and it will be appreciated that describedfeatures may be combined in any suitable combination. In particular, thefeatures of any one example embodiment may be combined with features ofany other embodiment, as appropriate, except where such combinations aremutually exclusive. Throughout this specification, the term “comprising”or “comprises” means including the component(s) specified but not to theexclusion of the presence of others.

Attention is directed to all papers and documents which are filedconcurrently with or previous to this specification in connection withthis application and which are open to public inspection with thisspecification, and the contents of all such papers and documents areincorporated herein by reference.

All of the features disclosed in this specification (including anyaccompanying claims, abstract and drawings), and/or all of the steps ofany method or process so disclosed, may be combined in any combination,except combinations where at least some of such features and/or stepsare mutually exclusive.

Each feature disclosed in this specification (including any accompanyingclaims, abstract and drawings) may be replaced by alternative featuresserving the same, equivalent or similar purpose, unless expressly statedotherwise. Thus, unless expressly stated otherwise, each featuredisclosed is one example only of a generic series of equivalent orsimilar features.

The disclosure is not restricted to the details of the foregoingembodiment(s). The disclosure extends to any novel one, or any novelcombination, of the features disclosed in this specification (includingany accompanying claims, abstract and drawings), or to any novel one, orany novel combination, of the steps of any method or process sodisclosed.

1. A method of a distributed unit (DU) in a wireless communicationsystem, the method comprising: receiving, from a central unit (CU),information related to an internet protocol (IP) header; identifying atleast one bearer based on the information related to the IP header; andmapping the at least one bearer to a backhaul channel.
 2. The method ofclaim 1, wherein the information related to the IP header includes an IPaddress, and information about an IPv6 flow label indicating an ipv6flow of DL traffic.
 3. The method of claim 1, wherein the informationrelated to the IP header includes information about a differentiatedservices code point (DSCP).
 4. The method of claim 1, furthercomprising: transmitting downlink traffic on the backhaul channel,wherein the DU is included in a donor base station (BS) in an integratedaccess and backhaul (IAB) network.
 5. The method of claim 1, furthercomprising: identifying a backhaul radio link control (RLC) channel,wherein mapping the at least one bearer to the backhaul channelcomprises: mapping between the at least one bearer and the backhaul RLCchannel based on the information related to the IP header.
 6. Adistributed unit (DU), the DU comprising: a transceiver; and at leastone processor coupled with the transceiver and configured to: receive,from central unit (CU), information related to an internet protocol (IP)header, identify at least one bearer based on the information related tothe IP header, and map the at least one bearer to a backhaul channel. 7.The DU of claim 6, wherein the information related to the IP headerincludes an IP address, and information about an IPv6 flow labelindicating an ipv6 flow of DL traffic.
 8. The DU of claim 6, wherein theinformation related to the IP header includes information about adifferentiated services code point (DSCP).
 9. The DU of claim 6, whereinthe at least one processor is further configured to: transmit downlinktraffic on the backhaul channel, and wherein the DU is included in adonor base station (BS) in an integrated access and backhaul (IAB)network.
 10. The DU of claim 6, wherein the at least one processor isfurther configured to: identify a backhaul radio link control (RLC)channel; and map between the at least one bearer and the backhaul RLCchannel based on the information related to the IP header.
 11. A methodof a central unit (CU) in a wireless communication system, the methodcomprising: transmitting, to a distributed unit (DU), informationrelated to an internet protocol (IP) header, wherein at least one beareris identified based on the information related to the IP header, andwherein the at least one bearer is mapped to a backhaul channel.
 12. Themethod of claim 11, wherein the information related to the IP headerincludes an IP address, and information about an IPv6 flow labelindicating an ipv6 flow of DL traffic.
 13. The method of claim 11,wherein the information related to the IP header includes informationabout a differentiated services code point (DSCP).
 14. The method ofclaim 11, wherein the DU and the CU are included in a donor base station(BS) in an integrated access and backhaul (IAB) network.
 15. The methodof claim 11, wherein the at least one bearer is mapped to a backhaul RLCchannel based on the information related to the IP header.